Tuning Your Slicer For Your Nozzle Size

If you’re looking at replacing your worn out old nozzle or wanting to experiment with different size nozzles, the first thing you should know is the effects of changing the bore size of the nozzle on the print and what settings you need to change in your slicer to get the best out of your 3D printer.

What size nozzle does my 3D printer come with?

On 90% of 3D printers, ranging from the Prusa MK3 to the Creality Ender 3, the standard nozzle size is 0.4mm. The only exception is with 3D printers like the Lulzbot Taz series which comes stock with a 0.5mm nozzle. The only other thing you need to consider is the thread size of nozzle. There are 3 common hotend types for 3D printers which all have different thread types, check our the differences between the three here:

• MK8 – Suitable for all Creality machines (Excluding CR-10S Pro/Max)
• E3D/RepRap – Suitable for any E3D/Slice Engineering/Prusa machine and more
• CR-10S Pro/Max – Unique nozzles for these printers. Have a 0.75mm thread pitch instead of 1mm.

How does nozzle size relate to my print?

The size or diameter of the nozzle is directly related to the extrusion width of the line the 3D printer can put down. Depending on what you do with 3D printing, this can affect how productive you can be and the quality of your prints in both positive and negative ways. The stock 0.4mm nozzle is the optimal size for balancing out between these two.

If you want to print small, intricate models or high precision parts, you will be wanting to print at the smallest layer heigh possible (0.1 – 0.05mm) and use as small a nozzle as possible (0.3 – 0.25mm). Printing at small layer heights with small nozzles results in an increased print time as the printer is limited to the volume of material it can extruder, which is a combination of layer height and extrusion width.

If you want to go to the other end of the spectrum and print parts as fast as possible with print quality being second to time, the bigger the nozzle the better. For a standard extruder, anything larger than a 0.8mm nozzle is not recommended as the hotend can’t maintain a constant temperature without slowing the speed down majorly, which is not what you want. Layer heights of up to 0.5mm nozzles are possible with a 0.8mm nozzle which can dratically increase print time.

What settings do I change in my slicer?

When you change your nozzle size, there are a few common things you want to change in the slicer no matter if you go up or down in size. These can be easily calculated using general rule of thumbs:

1. Max Layer Height = 50 – 75% of nozzle diameter
2. Extrusion width = 1.2 x nozzle diameter

When it comes to printing with a larger nozzle, there are a few things you will want to change to maintain the best possible quality without limiting the print time too much. These include:

1. Increase nozzle temperature 5° – 10°: As more material is flowing through the nozzle, this helps to maintain a constant temperature when the faster flow of filament is sucking all the heat away from the nozzle.
2. Reduce the perimeter count: As the extrusion width will now be close to 1mm, you won’t need as many perimeters for a similar wall thickness with a 0.4mm nozzle. It is advised to at least use a minimum of 2 walls to maintain decent print quality
3. Reduce speed: This helps to make sure the filament has enough time to heat up before it is extruded. 25mm/s or lower is recommended but even though we’re slowing it down, the overall print time is still significantly reduced.

For 3D printing with a smaller nozzle, it is almost the exact opposite of above. For fine detail and high-quality prints, these changes are what we suggest:

1. The layer height of 0.07-0.1mm: This minimum layer height helps to prevent any possible clogging as the nozzle would be too close to the printed part with nowhere for the filament to go.
2. Decrease nozzle temperature 5° – 10°: As less material is flowing through the nozzle, the hotend doesn’t have to work as hard to maintain the temperature. Reducing this reduces the chance of heat creep as the filament isn’t moving as fast.
3. Slow the print speed down: To get the best quality with as minimal ringing and unwanted artifacts in the prints, slow the printer down. Anywhere from 70% – 50% reduction is best. Slowing down the print increases overall quality as the precision is increased and the potential for overshoot is minimised.

With any nozzle you get, it is always good practice to run some test prints through it to get an idea of what settings you need to change. A temperature tower, extrusion multiplier test, and an overhang test are a couple of test prints that help finetune various issues you may encounter along the way such as stringing, poor overhangs, bad adhesion or issues with support material but majority of printers should have no issues with these basic changes.

We’d love to chat to you about your 3D Printing needs. Get in touch!